Police say the death of a Hutt Valley man may be linked to synthetic drugs, as the number of people admitted to emergency departments spikes in the region.

Police have confirmed a 36-year-old man died in the Hutt Valley on Thursday night and it is likely due to synthetic drugs, said Hutt Valley police area commander Inspector Sean Hansen.

Police have already seized a significant amount of synthetic drugs from addresses within the Hutt Valley and wider Wellington district and a number of arrests have been made, he said, as the focus on taking out suppliers continued.

Capital & Coast DHB, meanwhile, have confirmed 11 people have come to Wellington Hospital's emergency department in the past 10 days, experiencing the effects of what doctors believe to be synthetic drugs.

Five, all believed to be from Porirua, were admitted on November 7 and 8.

On Friday, a raid on a house in Cannons Creek, Porirua, seen as a major source for the drugs, was carried out.

Kapiti-Mana police area commander, Inspector Tracey Thompson, says as a precaution the Armed Offenders Squad was present during the early part of the search.

A man and a woman were arrested.

Since November 1, there have been 17 incidents related to synthetic drugs in Kapiti and Porirua.

"Police are focused on holding to account those who are manufacturing or supplying synthetic drugs," Thompson said.

The cases follow several incidents involving synthetic drugs in Auckland, which led the police to call it a "nationwide problem".

- NZ Newswire